HANGTIME SOUTHWEST — Did the Brooklyn Nets’ performances during Brook Lopez‘s seven-game injury absence classify him as their most irreplaceable player?

Perhaps. And not for the reason you’re probably thinking.

“It’s not even that (Lopez’s 18 points a game on 52.3 percent shooting),” coach Avery Johnson said during a telephone interview on Monday. “The kid was blocking almost three shots a game.”

Of course, it wouldn’t be an easy ride without their floor general, Deron Williams, even with him mired in a shooting slump and grinding through various aches and pains. Still, Lopez’s importance to Brooklyn becoming a contender in the East can’t be undersold after the Nets went 2-5 while he was sidelined with a mild strain to his left foot. It was the same foot he fractured prior to the start of last season, then injured again and ultimately reduced his fourth season to just five games.

“I just know when we had Brook Lopez in the lineup [this season before the injury] we were 10-4,” Johnson said, “and we could be a pretty good team.”

The foot injuries didn’t stop the Nets, now 13-10, from re-signing the 7-footer with the impressive set shot to a max deal during the summer once they finally had had enough of the Dwightmare and bowed out of the race for Dwight Howard‘s services.

The re-branded and re-cast Nets, having re-signed Gerald Wallace at a hefty price, traded for Joe Johnson and his enormous contract and maxed-out Williams, among other deals to bring in key role players, decided that the highly skilled and soft-spoken Lopez — the tame one compared to his wild-haired, less-talented twin brother Robin with the Hornets — would be their center for the future.

Without a doubt, Nets fans holding their breath for a Williams-Howard combo would closely watch Lopez’s progress — and especially his health — as Howard, a three-time defensive player of the year whose first choice was to play in Brooklyn, went to work with Kobe Bryant and the Los Angeles Lakers.

“Brook’s kind of got that Tim Duncan kind of personality,” Johnson said. “He’s not a rah-rah guy, he’s not a guy that’s going to talk a lot on the court, but he’s a great teammate, he’s talented and he’s improving defensively,” Johnson said. “And I think that’s what he wanted to prove more than anything, that he’s not going to be a defensive liability in the middle.

“He’s gotten stronger. He lifted more weights this summer than he ever has his whole career combined, so he’s maturing. When I first got the kid he was 21 going on 16. I’m really excited because he’s going to get so much better.”

The Nets are 1-1 in Lopez’s return with Johnson limiting his minutes to ease him back in. Brooklyn plays the Utah Jazz at home Tuesday and the Nets will be particularly giddy to have their big man up and running Wednesday night for their third meeting in three weeks against Tyson Chandler and the cross-town Knicks, and the first at Madison Square Garden.

Brooklyn won the opener, 96-89, with Lopez playing like a grown man — 22 points, 11 rebounds and five blocks. The Knicks won the second game a week ago, 100-97, with Lopez sidelined.

With Lopez out, the Nets allowed 9.2 points more a game than with him on the floor (90.7 compared to 99.9), and opponents shot markedly better when they didn’t have to deal with Lopez’s long arms defending the rim.

Lopez has 40 blocks, 11th in the league despite having missed seven games. He’s averaging a career-high 2.5 blocks a game, which ranks him sixth in the league, on par with Duncan (2.54) and Howard (2.56) and close to Roy Hibbert (2.96), NBA co-leaders Larry Sanders (3.00) and Serge Ibaka (3.00).

Last year when Lopez played in just five of 66 games, the Nets allowed 99.1 points a game. They’re allowing 93.8 this season. Credit much of that to Lopez’s presence in the paint. The Nets finished last season with 260 blocks, 70 fewer than their opponents and ranked last in the league averaging 3.9 a game.

They already have 118 blocks this season, 22 more than their opponents.

“He is blocking shots,” Johnson said of Lopez, whose previous career-best was 1.8 blocks a game as a rookie. “When people go down the middle they’re going to have to think twice because he’s going to go after it. And he’s having fun going after it.”